1. Field of the Invention
The present invention generally relates to an electromechanical apparatus for automatically controlling the temperature and/or volume of water delivered by a standard bath or shower fixture.
2. Description of the Prior Art
Various devices have been developed for providing automatic control of the temperature and pressure of water provided by water delivery fixtures. For instance, several systems use a microprocessor for electronic control of water delivery systems. The prior art devices typically employ proportional servo valve control in order to regulate the water supply lines. Although effective from a control standpoint, these servo controls are expensive and overly complex for the task at hand. In addition to providing overly complex solutions to the problem of controlling temperature and pressure, the prior art systems are typically difficult to install in an already existing shower fixture. Therefore, the prior art systems do not offer a practical solution to a consumer who desires to install an automatic water control device after construction of the consumer's residence.
An exemplary prior art device is set forth in U.S. Pat. No. 4,700,884 which discloses an electronic fluid control system that employs a number of special mixing and diverting valves. While this prior art system offers a solution to the problem of automatic control, it is not a practical solution for the owner of an existing home since all of the control valves and diverters are intended to be installed upstream of the existing shower fixture. Hence, this system would require the consumer to engage in an expensive and demanding installation process that would likely require extensive modification of the plumbing that leads to the shower fixture. Such plumbing modification would in turn require disassembly of some portion of the walls.
One recently issued patent made an attempt at a solution to the above retro-fit problem. U.S. Pat. No. 4,756,030, entitled "Bathroom controller", discloses a fluid controller that can be installed in an existing plumbing system without disturbing the existing faucets and manual control valves or alternatively used in a new installation. This noninvasive installation is achieved by leaving the existing hot and cold valves fully open and simply installing control valves, sensors, and circuitry upstream so that there is no need to damage the tiles or other finish surrounding the bath fixture. The patent recognizes that the access to pipes required for installation will in most cases require removal of a portion of dry wall or other wall panelling. Hence, the solution provided by U.S. Pat. No. 4,756,030 is unsatisfactory because it merely moves the problematic installation upstream from the area of the existing fixture to a remote location.